Meida



(No Model.)

J. J. DALMEIDA & J. Y. DA SILVA. ELECTRIC FIRE ALARM.

No. 484,386. Patented Oct. 18, 1892.

INVENTORS.

a m .a'ffinm WITNESSES: $21; 3. Zia/Jim;

M W. fz Saw M To all whom it may concern.-

subjects of the King of temperature, are

UNITED STATES PATENT OFFICE.

JOAQUIN JOSE DALMEIDA AND JOsE YGNACIO DA SILVA, OF LISBON,

PORTUGAL.

ELECTRIC FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 484,386, dated October 18, 1892.

Application filed May 2, October 8, 1890,1I0. landMarch 21,1891,No.5,12'7.

1890. SerialNo. 431,455- (Nomodel.

Be it known that we, JOAQUIN J OSE DAL- MEIDA and J osr'i YGNACIO DA SILvA, both Portugal, and residents of Lisbon, Portugal, have jointly invented certain Improvements in Electric Fire-Alarms, (for which patents have been granted in Spain, No. 11,207, dated November 5, 1890; in Portugal,No. 1,517, dated November 13, 1890; in Germany, No. 97,218, dated October 8, 1890; in France, No. 208,707, dated October S, 1890, and in Great Britain, No. 5,127, dated March 21, 1891,) of which the following is a specification.

Our invention relates to the cass of devices designed to give an alarm in case fire should break out in a room, through the medium of a generator of electricity and an annunciator, the sudden rise of temperature being utilized to establish a current of electricity in the circuit.

Broadly, our apparatus comprises a hermetically-closed vessel provided with two upright branches or parts containing air or aeriform gas. In said vessel is an exciting liquid, and in one of said branches, which is screened in such a way as to protect the air in it from the influence of a sudden rise of arranged the electrodes of a galvanic cell. The electrodes will be situated above the level of the exciting liquid in the branch and will have metal conductors, which project out through the wall of the branch where they may be put in circuit with anyelectrical annunciatororbell. IVhen the temperature in the room is suddenly raised, the air or gas in the exposed branch expands and forces the exciting fluid up in the opposite branch until it partly or wholly submerges the electrodes, and thus establishes a current of electricity in the circuit. Where the exciting liquid is an acid, means are provided for protecting the electrodes from its tumes.

Our invention will be more particularly described hereinafter, and its novel features carefully defined in the claims.

The accompanying drawing illustrates a partial embodiment of our invention.

Patented in Germany October 8. 1890, No. 97,218; in France 208,707; in Spain November 5,1S90,N0.1l,267; in Portugal November 13,1890,No.1,517, and in Eng- A B 0 represents a U shaped vessel of glass or other suitable material. This vessel may be in the form of a hermetically-closed bent tube with bulbs or enlargements A and B on its respective upright branches, which bulbs will contain air or other aeriform gas. The lower portion 0 may be curved, as shown, or straight. This vessel may be secured to a block D and this block be secured to the wall or other part of the room by a screw E. (Shown in shirt.) The bulb A is screened to protect the air within it from the direct influence ot a sudden rise in temperature of the ambient air, and this screening may be effected by inclosing the bulb A ina cover F. (Represented as partly broken away in the drawing.)

In the upright branch,below the screened bulb A, are placed the electrodes of a galvanic cell, consisting, as here shown, of a coil of platinum wire 19 and a rod or piece of zinc These electrodes will be arranged in close proximity but not in contact, and each will have a metallic conductor, which projects out through the wall of the inclosing vessel. If this vessel be of glass, they may be sealed in the glass with heat. The coil 19 may be made to fit snugly within the bore of the upright branch and the zinc may be pendent within the coil.

G represents an ordinary electric bell,which is in circuit with the pile through the medium of circuit-wires a a, connected with the respective conductors from the electrodes 1) and .2.

In the lower portion of the vessel is placed the exciting liquid l, which in this case may be nitric acid. The acid will rise in the upright branches of the vessel to about the level indicated by a: m, which level may be about three or four millimeters below the zinc However, this distance may be more or less, depending on the degree of delicacy desired for the apparatus.

On or over the nitric acid in the two up right branches of the vessel will be placed a supernatant hydrocarbon h, one of the derivatives of petroleum, having the formula 0, I1 This substance possesses the property of absorbing whatever vapors may arise from the acid, and it protects the electrodes therefrom. It may rise to the level indicated by y 3 in the drawing.

The operation of the apparatus is simple. Normal variations in temperature, being gradual, will heat the air in the two bulbs or res ervoirs A and B to substantially the same temperature; but should there be a sudden and considerable elevation of the temperature of the ambient aircaused, for example, by the breaking out of a fire in the room where the apparatus is placed-the air in the exposed bulb B will expand to a greater extent than that in the screened bulb A, and the tension in the former will depress the exciting liquid at that side and cause it to rise in the opposite branch until it reaches the electrodes 19 and .2, when a current will be established in the circuit and the bell or annunciator G will sound.

In the drawing, which represents the instrument above described about the natural size, the annunciator is represented as disproportionally small. This latter may be at any distance from the other portion of the apparatus.

Any means may be employed for screening the bulb A from the direct influence of a sudden rise of temperature in the ambient air. It is only essential that when there is such a sudden rise in the temperature the bulb B shall feel its effects first.

WVe do not wish to limit ourselves to the exact construction and form of the instrument herein shown, as these may be varied to some extent Without departing materially from our invention.

Having thus described our claim- 1. An electric alarm comprising a vessel containing an exciting liquid and the electrodes of a galvanic cell out of contact with the exciting liquid, the whole arrangement being such that upon a predetermined rise of heat the exciting liquid will contact with the electrodes, substantially as described.

2. An electric fire-alarm instrument comprising a hermetically-closed vessel containing an exciting liquid and having two upright branches, one of which is screened from the direct influence of heat in the surrounding air, and the electrodes of a galvanic cell arranged in said screened branch and above the level of the exciting fluid, each of said electrodes having a metallic conductorwhich projects out through the wall of the inclosing vessel.

3. An electric fire-alarm instrument comprising a hermetically-closed vessel containing nitric acid and a supernatant hydrocarbon, as set forth, and having two upright branches, one of which is screened from the direct influence of heat in the surrounding air, and the electrodes of a galvanic cell arinvention, we

ranged in said screened branch above the level of the acid, each of said electrodes having a metallic conductor which projects out through the wall of the inclosing vessel.

4. In an electric fire-alarm apparatus, the combination, with a U-shaped hermeticallyclosed vessel having enlarged portions or bulbs A and B on its upright branches and containing an exciting liquidZ in its lower portion 0, of the screen over one of said enlarged portions, the electrodes 19 and .2, arranged in the screened branch of the vessel above the normal level of the exciting liquid, an annunciator G, and a circuit of which the electrodes and the coils of the annunciator form a part, substantially as set forth.

5. The combination, with the hermeticallyclosed U-shaped vessel having bulbs A and B on its upright branches and containing nitric acid and supernatant hydrocarbon in its lower part, of the electrodes of a galvanic cell arranged in one of said upright branches above the normal level of the acid, an electrical annunciator, a circuit of which said electrodes and the coils of the annunciator form a part, and means for screening the air or gas in the bulb above the said electrodes, substantially as set forth.

6. The combination, with a hermeticallyclosed vessel having two upright branches containing air or aeriform gas, one of said branches being screened against heat, of an acid excitant in said vessel, electrodes of a galvanic cell in said screened branch and above the acid excitant, and a supernatant hydrocarbon interposed normally between said electrodes and the said excitant, Whereby the electrodes are protected from the fumes of the acid, as set forth.

7. In an electric fire-alarm instrument, the combination, with the closed U-shaped vessel containing a liquid excitant in its lower part and having one of its branches screened against a sudden rise in temperature, of the electrodes of a galvanic cell, comprising the platinum coil 20 in the bore of the screened branch of the vessel and the zinc z, pendent in said coil, but out of contact therewith, substantially as set forth.

8. An electric alarm comprising a vessel containing an exciting fluid and the elements of a galvanic cell normally out of contact with the exciting fluid and so arranged that upon a predetermined rise of heat the said fluid will expand and touch the said elements, thereby generating a current of electricity, substantially as set forth.

In witness whereof wehave hereunto sign ed our names in the presence of two subscribing witnesses.

JOAQUIN JOSE DALMEIDA. JOSE YGNACIO DA SILVA. lVitnesses:

ANTONIO PALHARES no CoNsoIo In Bm'zio, Josn MENDES nos SANTOS.

IIO 

